Integrated circuits are an important part of any electronic device. As more electronic devices rely upon battery power, it is important to reduce the power consumption in integrated circuits. One portion of an electronic device which consumes power is an input/output (I/O) port coupled to receive an input signal or generate an output signal. The power required in a particular circuit and overall in an integrated circuit may vary based upon the process, voltage and temperature, also known as PVT, associated with the integrated circuit. That is, depending upon the process used to manufacture the components such as transistors of the integrated circuit, the supply voltage applied to the integrated circuit, or the temperature of the integrated circuit or a portion of the integrated circuit, the power consumption of a given circuit will vary.
Conventional circuits and methods for implementing I/O ports use a local-biased amplifier in each I/O port. Not only do these local-biased amplifiers consume additional area on the integrated circuit, but they have high power consumption over various PVT combinations. More particularly, the power consumption will vary depending upon a supply voltage applied to the device. In order to reduce power consumption, it is beneficial to provide a circuit which is independent of variations in the PVT variables.